Lid of a packaging container

Abstract

To provide a lid for a packaging container that retains rigidity and visibility, and has a unique aesthetic appeal.SOLUTION: The lid for a packaging container obtained by molding a thermoplastic resin sheet material includes: a top plate with a flat top surface and in a polygonal shape in a plan view; sidewalls connected multilaterally around the top plate; and a flange connected horizontally around the bottom edges of the sidewalls. The upper corner on the top plate side in the vertical connection part of the adjacent side walls is composed of an upper chamfer with the corner cut in an inverted triangle shape with its top facing downward, while the lower corner on the flange side in the vertical connection part is composed of a lower chamfer with the corner cut in a triangle shape with its top facing upward. The upper chamfer is positively curved outward while the lower chamfer is negatively curved inward.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a lid for a packaging container formed by molding a sheet material made of a thermoplastic resin, and has a configuration that provides good visibility of the contents, maintains rigidity, and can impart aesthetic properties not found in other lids.

Background Art

[0002] Packaging containers made of thermoplastic resins, which are widely used in supermarkets, convenience stores, etc., protect the foodstuffs stored in the containers and require rigidity that does not cause buckling not only in the container body but also in the lid when stacking and displaying the containers. Generally, in order to improve the rigidity of a packaging lid, reinforcing ribs are often provided on the top surface and side walls of the lid. However, attaching ribs to these locations has the problem of reducing the visibility of the foodstuffs inside the container.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the invention described in Patent Document 1, as a means for maintaining the rigidity of the lid, a plurality of vertical ribs are formed on the side wall portion. However, there is a problem that the visibility from the side direction is inferior due to the ribs provided on the side wall portion. In the invention described in Patent Document 2, similarly, ribs are provided on the side wall portion of the lid, so the visibility from the side direction is inferior.

[0005] Thus, in this type of packaging container, the contents are primarily visible through the lid, and for items such as sashimi and prepared foods, it is important to appeal to the visual sense to stimulate purchasing intent. Therefore, it is necessary to ensure visibility from all directions, not only from directly above, but also from diagonally above and from the side, so that the overall appearance of the contents can be grasped. Furthermore, considering differentiation and identifiability from other containers, it is preferable that the lid is also formed with a unique design.

[0006] This invention has been made in view of the above-mentioned problems, and its objective is to provide a lid for a packaging container that maintains rigidity, is highly visible, and possesses a unique aesthetic appeal. [Means for solving the problem]

[0007] To achieve the above-mentioned objectives, the present invention provides a lid for a packaging container made by molding a sheet material made of thermoplastic resin, comprising a top plate portion having a polygonal shape in plan view with a flat top surface, side wall portions connected around the periphery of the top plate portion, and flange portions connected horizontally around the lower end of the side wall portions, wherein in the vertical connection portions between adjacent side wall portions, the upper corner on the top plate portion side is formed by an upper chamfered portion cut into an inverted triangular shape with the top pointing downwards, while the lower corner on the flange portion side of the vertical connection portions is formed by a lower chamfered portion cut into an upward-pointing triangular shape, wherein the upper chamfered portion is a positive curved surface that bulges outwards, while the lower chamfered portion is a negative curved surface that concaves inwards.

[0008] With this method, visibility is excellent not only when viewed from directly above because the top surface is flat, but also because there are no ribs or anything like that on the side walls (partially), resulting in a state where the entire surface is glass, ensuring visibility from all directions, including from diagonally above and from the side.

[0009] Furthermore, regarding rigidity, the vertical connection between adjacent side walls is a crucial part. In this invention, the upper and lower corners are composed of an upper chamfer and a lower chamfer, and the contours of these chamfers are inverted triangles and triangles. As a result, similar to a truss structure, stable high strength is obtained, the resistance to bending and twisting is increased, and rigidity can be maintained without the use of ribs.

[0010] Furthermore, in this invention, since the upper and lower chamfered sections are composed of positive and negative curved surfaces, a kind of lens effect is obtained, creating a unique aesthetic.

[0011] Furthermore, the vertically connected sections of adjacent side walls may have a flat, corner-cut intermediate chamfer between the upper and lower chamfered sections, thereby adding aesthetic variation while maintaining visibility and rigidity.

[0012] Separately, having a straight, angular protruding corner between the upper and lower chamfered sections can provide a different aesthetic appearance than that achieved with the intermediate chamfered section, and by adjusting the length of the protruding corner, it is also possible to increase the height of the lid (side wall) while maintaining rigidity.

[0013] Furthermore, when the upper and lower chamfered sections are directly connected at their respective tops, the overall aesthetics can be simplified compared to those with intermediate chamfered sections or protruding corners as described above.

[0014] On the other hand, the flange portion has a protruding rib on the extension of the vertical connecting section between adjacent side walls, and by intersecting this rib with the bottom edge of the lower chamfered section in a T-shape, the rib enhances the sense of unity between the side wall portion and the flange portion, further improving rigidity against bending and twisting. [Effects of the Invention]

[0015] According to the present invention, in the vertical connecting portion between the adjacent side wall portions, the upper corner on the top plate portion side and the lower corner on the flange portion side are respectively chamfered into an inverted triangular shape and a triangular shape, so that while maintaining the overall visibility, excellent rigidity due to the truss structure can be obtained. Moreover, since these upper and lower chamfered portions are positive and negative curved surfaces, a lid for a packaging container having a unique aesthetic property can be provided.

Brief Description of the Drawings

[0016] [Figure 1] Perspective view of a packaging container according to an embodiment of the present invention [Figure 2] Same, plan view [Figure 3] Same, side view [Figure 4] Same, enlarged plan view of the main part according to Example 1 [Figure 5] Same, end view taken along line A - A [Figure 6] Same, enlarged plan view of the main part according to Example 2 [Figure 7] Same, end view taken along line B - B [Figure 8] Same, enlarged plan view of the main part according to Example 3 [Figure 9] Same, end view taken along line C - C [Figure 10] Same, end view of the fitting portion showing the closed - lid state by the lid [Figure 11] Same, end view of the non - fitting portion showing the closed - lid state by the lid

Embodiments for Carrying out the Invention

[0017] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view of a packaging container according to an embodiment of the present invention, showing the lid body 10 and the container body 20 separated. Further, FIG. 2 is a plan view, and FIG. 3 is a side view. The lid body 10 has a flange portion 11 that is attached to the opening edge portion of the container body 20 from the outside. A skirt portion 12 is vertically provided at the periphery of this flange portion 11. Further, a concave lid body fitting portion 13 that externally fits into the main body fitting portion 21 is formed at a key position of the skirt portion 12. The portion that protects the contents placed on the container body 20, etc. is composed of a top plate portion 1 and side wall portions 2 that are continuously provided around it and are also continuously provided adjacent to each other.

[0018] The top plate portion 1 is entirely composed of a plane and is rectangular in plan view in this embodiment. And corresponding to the four sides of the top plate portion 1, four-sided side wall portions 2 are continuously provided around it. Further, a flange portion 11 is provided horizontally around the lower part of the side wall portion 2. Note that the plan view shape of the top plate portion 1 is not limited to a rectangle and may be a square, or other polygons can be adopted.

[0019] In the lid body 10 having such a basic configuration, the characteristic part of the present invention is at the corner part in the height direction from the four corners of the top plate portion 1 toward the flange portion 11, that is, at the vertical continuous portion 3 where adjacent side wall portions 2 are continuously provided. The maximum characteristic is that this continuous portion 3 is formed into a triangular shape with different directions in the upper and lower stages and a curved surface configuration with different concavities and convexities. Since there are a plurality of variations in the configuration of this continuous portion 3, each of Examples 1 to 3 will be described according to FIGS. 4 to 9.

Example

[0020] Figure 4 is an enlarged plan view of the main part showing the corner portion of the lid 10 according to Embodiment 1, and Figure 5 is a cross-sectional view thereof along line AA. In this Embodiment 1, the vertical connecting portion 3 of adjacent side wall portions 2 is composed of an upper chamfered portion 4 and a lower chamfered portion 5. As is clear from Figure 4, the plan view shapes of these portions are such that the upper chamfered portion 4 is formed by cutting the corner including the corner of the top plate portion 1, and the top portion 4a has the shape of an inverted triangle pointing downwards. In contrast, the lower chamfered portion 5 is formed by cutting the corner including the corner on the inside (connecting portion 3 side) of the flange portion 3, and the top portion 5a has the shape of an upward-pointing triangle.

[0021] These chamfered sections 4 and 5 have distinctive features not only in their contours but also in their cross-sectional shapes. Specifically, as shown in Figure 5, the upper chamfered section 4, which is demarcated by an inverted triangular contour, has a positive curved surface that bulges outward, while the lower chamfered section 5, which is demarcated by a triangular contour, has a negative curved surface that concaves inward.

[0022] Furthermore, as a configuration unique to this embodiment 1, a planar intermediate chamfer 6 is formed between the upper chamfer 4 and the lower chamfer 5. In this embodiment 1, a portion of the top 5a side of the lower chamfer 5 is left flat to form the intermediate chamfer 6. Therefore, the lower chamfer 5 is strictly trapezoidal in embodiment 1. [Examples]

[0023] Figures 6 and 7 show Embodiment 2, in which the vertical connecting portion 3 of the side wall portion 2 is composed of an inverted triangular upper chamfered portion 4 and a triangular lower chamfered portion 5, and the upper chamfered portion 4 is a positive curved surface while the lower chamfered portion 5 is a negative curved surface, which is the same as Embodiment 1. However, in Embodiment 2, a protruding corner portion 7 is provided between the upper chamfered portion 4 and the lower chamfered portion 5, connecting the respective vertices 4a and 5a in a straight line. [Examples]

[0024] On the other hand, Figures 8 and 9 show Example 3, in which nothing is formed between the upper chamfered portion 4 and the lower chamfered portion 5, and their respective tops 4a and 5a are directly connected. Otherwise, the plan view shape and cross-sectional shape of these chamfered portions 4 and 5 are the same as in Examples 1 and 2.

[0025] All of these embodiments 1 to 3 exhibit the same effects in terms of visibility and rigidity. In other words, in this embodiment, because the top plate 1 is flat, visibility is good when viewed from directly above, and because there are no ribs or the like in the middle of the side wall 2, it is essentially a glass-enclosed surface, ensuring visibility in all directions, including from diagonally above and from the side.

[0026] Furthermore, regarding rigidity, by constructing the vertical connecting sections 3 between adjacent side wall sections 2 with an inverted triangular upper chamfered section 4 and a triangular lower chamfered section 5, stable high strength can be obtained, similar to a truss structure, increasing resistance to bending and twisting, and allowing rigidity to be maintained without ribs.

[0027] Furthermore, the curved surfaces of both the upper chamfered section 4 and the lower chamfered section 5 create a unique aesthetic due to a kind of lens effect. Moreover, the presence or absence of the intermediate chamfered section 6 and the protruding corner section 7 between the upper chamfered section 4 and the lower chamfered section 5 results in different aesthetic qualities for each of the three embodiments.

[0028] While the above configuration satisfies both visibility and aesthetics, a protruding rib 8 is formed on the flange portion 11 to further improve rigidity. In this case, the rib 8 is formed on the extension of the vertical connecting portion 3 of the side wall portion 2 (synonymous with the center line of the connecting portion 3, and on the imaginary line 9 passing through the tops 4a and 5a of the upper and lower chamfered portions 4 and 5). More preferably, one end of the rib 8 is directly connected to the bottom of the lower chamfered portion 5 in the connecting portion 3, without the use of grooves or the like. As a result, the rib 8 and the lower chamfered portion 5 are continuous, which enhances the sense of unity between the flange portion 11 and the side wall portion 2 and improves the overall rigidity.

[0029] Incidentally, when closing the container body 20, the lid 10 employs an external fitting structure in which the lid fitting portion 13 engages with the lower surface of the opening edge of the container body 20, as shown in Figure 10. By providing lid fitting portions 13 at multiple locations on the skirt portion 12, the overall fitting force is increased, preventing the lid 10 from opening unintentionally.

[0030] In such an external fitting structure, when opening the lid 10, it is common to start from a point where it is easy to grip the lid 10 with one's fingers, that is, one of the four corners. Therefore, in this invention, the lid fitting portion 13 is not formed on the extension line of the connecting portion 3, which serves as the baseline for forming the rib 8 of the protrusions described above (see the end view in Figures 5, 7, and 9). As a result, as shown in Figure 11, the extension line of the connecting portion 3 in the skirt portion 12 becomes a non-fitting portion where the lid fitting portion 13 is not formed, making it easier to open the lid 10 starting from this point.

[0031] In particular, in this embodiment, when opening the lid by pinching the non-fitting portion of the skirt portion 12, deformation of the flange portion 11 is suppressed by the rib 8, and furthermore, the sense of unity between the flange portion 11 and the side wall portion 2 due to the direct connection of the rib 8 transmits the force used to pinch the non-fitting portion of the skirt portion 12 to the flange portion 11 and the side wall portion 2, making it easier to open the lid. [Explanation of symbols]

[0032] 1. Top panel 2 Side wall section 3 consecutive parts 4. Upper chamfered section 4a Top 5. Lower chamfered section 5a Top 6. Intermediate chamfered section 7 Extruded corner 8. Ribs 9 Virtual lines 10 Lid 11 Flange section 12 Skirt section 13 Lid fitting part 20 Container body

Claims

1. A lid for a packaging container made by molding a sheet material made of thermoplastic resin, The top surface is a polygonal shape in plan view, Side wall sections connected to each side of the top plate section, It comprises a flange portion that is horizontally connected around the lower end of the side wall portion, In the vertical connection between adjacent side wall sections, the upper corner on the top plate side is, It is composed of an upper chamfered section with a downward-pointing, inverted triangular shape at the top, In the aforementioned vertically connected section, the lower corner on the flange side is, It is composed of a lower chamfered section with a triangular top that points upwards and has its corners cut off, The aforementioned upper chamfered portion is a curved surface that bulges outward, The lower chamfered portion is a negative curved surface that is concave inward. The aforementioned vertically connected section has a flat, corner-cut intermediate chamfered section between the upper chamfered section and the lower chamfered section. A lid for a packaging container characterized by the following features.

2. The lid for a packaging container according to Claim 1, wherein the flange portion has a protruding rib on the extension of the vertical connecting portion, and the rib intersects the bottom portion of the lower chamfered portion in a T-shape.

Images